1. Field of the Invention
This invention relates generally to an apparatus in which an input video signal is frequency-modulated (FM-modulated) and recorded on a record medium, and more particularly is directed to a video signal recording apparatus which records the video signal and a related audio signal in the same tracks on a record medium.
2. Description of the Prior Art
A recording system of a prior art video tape recorder (VTR) will now be described with reference to FIG. 1 in which a video signal S.sub.V is shown to be applied to an input terminal 1. This video signal S.sub.V is supplied to a low pass filter 2 which separates a luminance signal component Y from the video signal S.sub.V. This luminance signal component Y is emphasized, in its high frequency band, by a pre-emphasis circuit 3 and then fed to a frequency-modulating circuit 4, in which it is frequency-modulated such that, for example, the white peak level becomes 5.4 MHz and the sync. chip level becomes 4.2 MHz. A frequency-modulated luminance signal Y.sub.FM from frequency-modulating circuit 4 is supplied to an adding or composing circuit 5.
The video signal S.sub.V applied to the terminal 1 is also supplied to a band pass filter 6 which separates a chrominance signal component C from the video signal. The chrominance signal component C is supplied to a chrominance signal processing circuit 7 in which the chrominance signal component C is frequency-converted and subjected to other signal processing to provide a low frequency converted chrominance signal C.sub.D whose color sub-carrier frequency is, for example, converted to 743 kHz. This low frequency converted chrominance signal C.sub.D is also supplied to composing circuit 5.
Further, an audio signal S.sub.A applied to a terminal 8 is supplied therefrom to an audio signal processing circuit 9. The audio signal processing circuit 9 effects signal processing, such as, frequency-modulation, of the audio signal S.sub.A and generates a frequency-modulated audio signal A.sub.FM whose carrier frequency is converted to, for example, 1.5 MHz. This frequency-modulated audio signal A.sub.FM is also supplied to composing circuit 5.
From composing circuit 5, there is derived a composite signal S.sub.R having the frequency spectrum shown in FIG. 2 and which is composed of frequency-modulated luminance signal Y.sub.FM, low frequency converted chrominance signal C.sub.D and frequency-modulated audio signal A.sub.FM. The composite signal S.sub.R is supplied through a recording amplifier 10 to rotary magnetic heads 11A and 11B which operate alternately to record the composite signal S.sub.R in successive oblique tracks on a magnetic tape 12.
In the above described prior art recording apparatus, if the low frequency components of the frequency-modulated luminance signal Y.sub.FM are emphasized, the resolution is increased and hence the picture quality can be improved. However, if the low frequency components of the frequency-modulated luminance signal Y.sub.FM are emphasized at all times, for example, as disclosed in Japanese Published Patent Application No. 47-137, there is the danger that this emphasis will exert a bad influence on the adjacent frequency-modulated audio signal A.sub.FM and hence the tone quality will be deteriorated. For example, when the video signal S.sub.V is generated by a home video camera and has a relatively narrow frequency band, the relationship between the frequency-modulated luminance signal Y.sub.FM and the frequency-modulated audio signal A.sub.FM is as shown by a solid line in FIG. 3A. In that case, even if the low frequency component of the frequency-modulated luminance signal Y.sub.FM is emphasized, as shown by the broken line in FIG. 3A, the level of the emphasized frequency-modulated luminance signal Y.sub.FM in the frequency band of the frequency-modulated audio signal A.sub.FM is low so that no trouble results therefrom. However, when the video signal S.sub.V is the output from, for example, a television tuner, a video disc reproducing apparatus or other source of a video signal with a relatively wide frequency band, the relationship between the frequency-modulated luminance signal Y.sub.FM and the frequency-modulated audio signal A.sub.FM is as shown by a solid line in FIG. 3B. Accordingly, if the low frequency component of the frequency-modulated luminance signal Y.sub.FM is emphasized, as shown by a broken line in FIG. 3B, the level of the frequency component of the frequency-modulated luminance signal Y.sub.FM in the frequency band of the frequency-modulated audio signal A.sub.FM is relatively high, and this exerts a bad influence upon the frequency-modulated audio signal A.sub.FM and thus the tone quality is deteriorated.